Support winch with grease supply

ABSTRACT

The invention describes an arrangement of lubricating grease ( 2 ) inside the housing of a gear unit ( 1 ) with rotatable components, particularly the gear unit of a jack ( 5 ). It also describes a grease pouch ( 3 ) for receiving lubricating grease ( 2 ) and a method for lubricating the gear unit ( 1 ) with lubricating grease.  
     Since the gear units ( 1 ) are often not transported in their installed position, oil that has separated from the lubricating grease may leak from any gearbox openings.  
     Thus, one of the objects of the invention was to provide an arrangement of lubricating grease ( 2 ) in the housing of a gear unit, which on the one hand provides lubrication of the gear unit ( 1 ) so that it is ready for operation in its delivery condition and on the other hand effectively prevents the oil separated from the lubricating grease ( 2 ) from leaking prior to initial startup.  
     This object is attained by enclosing the lubricating grease ( 2 ) within at least one grease pouch ( 3 ) prior to initial startup of the gear unit ( 1 ). The at least one grease pouch ( 3 ) is inserted into the housing of the gear unit ( 1 ) so as to contact the components. Upon initial startup the at least one grease pouch ( 3 ) is torn open by the action of the components and releases the lubricating grease ( 2 ).

[0001] The invention relates to an arrangement of lubricating grease inthe housing of a gear unit having rotatable components, particularly thegear unit of a jack. The invention further relates to a grease pouch forreceiving lubricating grease and, further, to a method for lubricatinggear units with lubricating grease.

[0002] Gears are commonly lubricated with lubricating grease beforedelivery and are thus delivered to the customer in a condition ready foruse. Because the gears are often not transported in their installedposition but, e.g., lying flat, and the lubricating grease releases oilafter even a relatively short storage period, this oil may run out ofgearbox openings.

[0003] This problem occurs, for example, in landing gears that are to bemounted in pairs on semi-trailers of tractor-trailer units. Theyessentially comprise a support tube with an inner tube that can betelescoped by means of a drive shaft and a gear mechanism.

[0004] The major drawback of the leaking oil, in addition to theenvironmental pollution it causes, is that the oil runs down on theoutside of the gearbox and must be removed in a time-consuming processprior to any subsequent paint job. Otherwise it is impossible to obtaina satisfactory painting result.

[0005] It has therefore been attempted in the manufacture of the jacksto make the gearbox completely oil-tight to the outside. In practice,however, the results were only partially satisfactory. Although it waspossible to obtain a seal in the area of a lid sealing the support tubeby introducing a sealing compound between the lid and the support tubeand to seal the feed-through of the primary shaft, a solution to theproblem of sealing the connecting shaft opening has thus far remainedelusive.

[0006] Thus, one of the objects of the invention was to provide alubricating grease arrangement in a gear housing making it possible onthe one hand to provide ready-to-use lubrication of the gearing in itsdelivery condition and on the other hand effectively to prevent any oilthat may have separated from the lubricating grease from leaking priorto initial startup.

[0007] A further object was to develop an optimized grease pouch forreceiving lubricating grease.

[0008] Yet another object was to develop a method for greasing a gearunit making it possible to introduce the lubricating grease prior todelivery and at the same time to prevent the loss of oil that may haveseparated from the lubricating grease.

[0009] According to the invention, these objects are attained by anarrangement in which the lubricating grease is enclosed by at least onegrease pouch prior to initial startup of the gear unit. The at least onegrease pouch is inserted into the gearbox on at least one rotatablecomponent. Through the action of the rotatable component the at leastone grease pouch tears open when the gear unit is initially operated andreleases the lubricating grease.

[0010] Due to the rotary motion of the rotatable components, e.g. theshafts and the gear wheels, the lubricating grease is uniformlydistributed within the gear unit upon initial use.

[0011] To ensure that the grease pouch is reliably torn open, at leastone edge of the grease pouch is preferably arranged on a gear wheel ofthe gear unit. As soon as this gear wheel of the gear unit begins torotate upon initial startup, the entire grease pouch is caught by itsedge and pulled into the gear unit. Inside the gear unit, the greasepouch is torn open and the lubricating grease is distributed by therotating gear parts.

[0012] It is advantageous if the grease pouch is under pressure becausethis facilitates the tearing of the grease pouch. This can beaccomplished, for example, by a special configuration, e.g., of agearbox cover that is equipped with ribs pushing against the greasepouch.

[0013] A special embodiment relates to the arrangement of lubricatinggrease in the gears of a jack. The gears at least partially arrangedinside a gear chamber formed by a support tube and a gear cover. It isequipped with a shaft, particularly an intermediate shaft, having afirst bevel gear. The first bevel gear meshes with a second bevel gearthat is non-rotatably mounted on the gear-side end of a spindle. Byrotating the shaft in a first direction of rotation, an inner tubemounted inside the support tube and engaging with the spindle via aspindle nut can be telescoped in an extension direction. The lubricatinggrease is completely enclosed by a grease pouch. This grease pouch isplaced into the gear chamber with at least one edge on the first bevelgear and/or the second bevel gear. Upon initial startup of the jack, thebevel gears start to rotate, catch the edge of the grease pouch and pullthe entire grease pouch between the first and the second bevel gear,such that during the first pass of the grease pouch through the bevelgears the lubricating grease is already squeezed out and distributedwithin the gear unit.

[0014] Preferably, the grease pouch is arranged in the gear chamber on apull-in side of the bevel gears in the first direction of rotation. As aresult, the grease pouch does not need to position itself independentlybut is already inserted in an appropriate position prior to delivery ofthe jack directly in front of the bevel gears on the pull-in side of thebevel gears. Because the jacks are always delivered in their retractedstate, and the customer can therefore move the jack only in theextension direction upon initial startup, the direction of rotation ofthe bevel gears is likewise predetermined at the time of initialstartup, and the pull-in side of the cooperating bevel gears is thusdefined.

[0015] Advantageously, the width of the grease pouch largely correspondsto the diameter of the second bevel gear.

[0016] Preferably, the diameter of the second bevel gear, in turn,corresponds approximately to the inside width of the gear chamber. Thewidth of the grease pouch essentially determines the shape of the pouchfor a given amount of lubricating grease. If the width of the greasepouch is clearly greater than the diameter of the second bevel gear,wall friction increases substantially and the grease pouch may not bepulled in at all or only incompletely. On the other hand, if the greasepouch is clearly narrower but has the same length and contains a givenminimum amount of lubricating grease, it becomes too full. Again, thebevel gears may not pull it in and destroy it at all or onlyincompletely. In either case, the gearing will not be adequatelysupplied with lubricating grease.

[0017] Advantageously, the at least one edge of the grease pouch isfixed to at least one bevel gear and/or to the shaft, particularly to anintermediate shaft, by means of an adhesive. This further increases theprobability that the grease pouch will be caught and pulled in. Asuitable adhesive is, for example, a spray adhesive.

[0018] As an alternative or in addition to the use of an adhesive, theedge of the grease pouch may be provided with a mounting tab that can beguided between the intermediate shaft and the second bevel gear.

[0019] Preferably, the gear cover is provided with blocking ribsprotruding into the interior and acting on the grease pouch.

[0020] In jacks of the prior art, the gear cover is frequentlyconfigured with a circumferential supporting rim protruding on theunderside and with a protruding cross rib. In this connection it may beadvantageous to provide additional blocking ribs on the supporting rimand the cross rib. While the cross rib primarily serves to stiffen thegear cover, the function of the blocking ribs, after insertion of thegrease pouch, is to push the grease pouch against the components of thegear unit, e.g. the bevel gears, as the gear cover is closed. As aresult, the grease pouch can be made smaller and can be filled with lesslubricating grease. This, in turn, reduces costs and the amount ofgrease pouch material to be ground up by the gears.

[0021] In addition, the blocking ribs prevent the grease pouch or largerquantities of lubricating grease from getting stuck in the cross rib andthus improve the lubrication of the moving gear parts.

[0022] The one further object is attained by a grease pouch made of acomposite material. The individual layers of this composite materialhave different functions. The composite material preferably has an innerpolyethylene layer, an aluminum layer applied thereto, an intermediatepolyethylene layer and an outer paper layer. The polyethylene layers arenecessary to weld the pouch material together along the edges. Thealuminum layer ensures that the oil or lubricating grease cannot getthrough to the outside and thus represents a barrier layer. The paperhas a relatively rough surface and is relatively easily caught and tornopen by the gearing components.

[0023] Preferably, the inner polyethylene layer has a weight per unitarea of 20 g/m² to 30 g/m², the aluminum layer has a thickness of 5 μmto 10 μm, the intermediate polyethylene layer has a weight per unit areaof 10 g/m² to 15 g/m², and the outer payer layer has a weight per unitarea of 20 g/m² to 50 g/m². Such a layer structure of the compositematerial ensures on the one hand that the lubricating grease is tightlyencapsulated and on the other hand scarcely affects the running behaviorof the gear unit after release of the lubricating grease. This isapparent, for example, from a change in the energy required to displacethe jack, which is not noticeable to the operator of the jack.

[0024] The outer shape of the grease pouch can be rectangular with twoopposite longitudinal edges and two opposite face edges. If the greasepouch is rectangular, a first longitudinal edge can be made as a foldededge while the opposite second longitudinal edge as well as the faceedges can be welded edges. This is a very simple solution in terms ofproduction since only three sides need to be welded despite therectangular shape. In addition, production tolerances and scrap arereduced because the grease pouch is made of a single piece of materialand the topside is less likely to shift relative to the underside whenthe grease pouch is manufactured.

[0025] Advantageously, the width of the welding edge increases by atleast one face edge in the direction of the longitudinal edges. Thisagain makes it easier for the grease pouch to be pulled into the gearingbecause the first bevel gear is often arranged in an edge area of thegearbox and the welded edge interacting with the first bevel gear iswider in this edge area in the above-described embodiment of the greasepouch. To minimize errors during inserting of the grease pouch prior tothe delivery of the gear unit, the width of the welded edge shouldincrease symmetrically in the direction of the longitudinal edges.

[0026] It has been found to be particularly advantageous if the greasepouch is dimensioned to receive a lubricating grease amount ranging from160 g to 200 g. This amount of lubricating grease ensures lubrication ofthe gearing of the jack and at the same time clearly reduces the amountof lubricating grease required as compared to the prior art. This is dueto the fact that the lubricating grease is applied directly to themoving components of the gearing and that the filling of cavities withinthe gear chamber is thereby avoided.

[0027] The second further object is attained by a method in which atleast one pouch filled with lubricating grease is brought into contactwith the gearing prior to startup. Upon startup of the gear unit, atleast one component of the gearing tears open the at least one greasepouch so that the lubricating grease is released and lubricates thegearing. After startup, the at least one grease pouch remains in thegearing. The great advantage of this method is that it does not requireany structural changes to be made in either the gearing or the supporttube surrounding the gearing.

[0028] Preferably, the at least one grease pouch disintegratesautomatically. In this case, one or more gelatin capsules may be used asgrease pouches.

[0029] However, the grease pouch is advantageously ground up by thegearing, so that the grease pouch is shredded after the jack has beenmoved several times, and the ground up parts of the grease pouchremaining in the gearing do not have any negative effects.

[0030] The invention will now be described in greater detail, by way ofexample, with reference to six drawing figures in which:

[0031]FIG. 1 is a longitudinal section of an upper part of a jack filledwith lubricating grease,

[0032]FIG. 2 is a view according to FIG. 1 with inserted grease pouchprior to initial startup,

[0033]FIG. 3 is a top view of an open jack with inserted grease pouchprior to initial startup,

[0034]FIG. 4 is a top view of a grease pouch,

[0035]FIG. 5 is a bottom view of a gear cover, and

[0036]FIG. 6 is a longitudinal section taken along line A-A in FIG. 5.

[0037]FIG. 1 shows a longitudinal section of an upper part of a jack 5that is conventionally filled with lubricating grease.

[0038] The gear unit 1 is arranged within the support tube 6 and drivesa spindle 12, which displaces a spindle nut 14 that is fixedly connectedwith the inner tube 15 in extension direction 16 as the spindle rotates.At the gear-side end 13 of the spindle 12, the spindle 12 isnon-rotatably connected with the second bevel gear 11, which in turncooperates with the first bevel gear 10, which is non-rotatably mountedon the intermediate shaft 9. When the intermediate shaft 9 rotates in afirst direction of rotation 17, the inner tube 15 moves in extensiondirection 16.

[0039] To ensure lubrication of the gear unit 1, the gear chamber 8,which is open to the bottom and is formed by the support tube 6 and thegear cover 7, has been filled with lubricating grease 2 up to thefilling level 2 a. After a separation of oil (not depicted) from thelubricating grease 2, this oil frequently escapes through the shaftfeed-through 30 of the intermediate shaft 9, for which a successful sealhas not as yet been developed.

[0040]FIG. 2 shows a view similar to that of FIG. 1 with inserted greasepouch 3 prior to initial startup. Here, the grease pouch 3, with atleast one edge 4, particularly the face edge 27, lies fully against thesecond bevel gear 11 and at the same time contacts the first bevel gear10, as may be seen in FIG. 3.

[0041]FIG. 3 shows the jack 5 in a top view without the gear cover 7,again with inserted grease pouch 3 prior to initial startup. The greasepouch 3 has been inserted on the pull-in side 18 of the bevel gears 10,11, which in an extension direction 16 (see FIG. 1) is defined by thecorresponding first direction of rotation 17 of the intermediate shaft9.

[0042] The top view of FIG. 3 further shows that the width 19 of thegrease pouch 3 corresponds approximately to the diameter 20 of thesecond bevel gear 11 and that the second longitudinal edge 26 liesagainst the first bevel gear 10 even prior to initial startup.

[0043] When the intermediate shaft 9 rotates in a first direction ofrotation 17, the face edge 27 (cf. FIG. 4) is caught and pulled in bythe intermediate shaft 9 and the second bevel gear 11 or, in a firstphase, by the first bevel gear 10.

[0044] In a subsequent phase, the first bevel gear 10 engages primarilywith the second longitudinal edge 26 of the grease pouch 3, while thesecond bevel gear 11 rotating in a direction of rotation 31 transportsthe grease pouch 3, which is now partially open and squeezed out, on thepull-in side 18 in the direction of the first bevel gear 10.

[0045] In a final phase, the grease pouch 3 is pulled through completelybetween the first and the second bevel gear 10, 11 and is largelydestroyed in subsequent rotations.

[0046]FIG. 4 is a top view of the grease pouch 3, which has a firstlongitudinal edge 25 configured as a folded edge and an opposite, secondlongitudinal edge 26 made as a welded edge 28. The two face edges 27 arelikewise made as welded edges 28, with a mounting tab 21 being fixed toone face edge 27. The mounting tab 21 can already be inserted betweenthe intermediate shaft 9 and the second bevel gear 11 during assemblyand is preferably glued to the intermediate shaft 9 by means of a sprayadhesive.

[0047] On the welded edges 28, corresponding to the width 29, thetopside 32 and the underside (non depicted) of the grease pouch 3 arejoined together in a material-based coupling. Due to the flatconfiguration of the welded edge 28, the gear teeth of the bevel gears10, 11 engage with this edge 28 particularly effectively.

[0048]FIG. 5 is a bottom view of the gear cover 7 with a supporting rim22 and a cross rib 23, which serves to increase stability. To preventthe grease pouch 3 from getting stuck on the underside of the gear cover7 between the cross rib 23 and the supporting rim 22, additionalblocking ribs 24 are formed.

[0049] The height 34 of the blocking ribs 24 corresponds to the height33 of the cross rib 23, as may be seen in the longitudinal section takenalong line A-A of the gear cover 7 in FIG. 6.

[0050] List of Reference Numerals

[0051]1 gear unit

[0052]2 lubricating grease

[0053]2 a filling height of lubricating grease

[0054]3 grease pouch

[0055]4 edge

[0056]5 jack

[0057]6 support tube

[0058]7 gear cover

[0059]8 gear chamber

[0060]9 intermediate shaft

[0061]10 first bevel gear

[0062]11 second bevel gear

[0063]12 spindle

[0064]13 gear-side end of spindle

[0065]14 spindle nut

[0066]15 inner tube

[0067]16 extension direction

[0068]17 first direction of rotation

[0069]18 pull-in side of the bevel gears

[0070]19 width of grease pouch

[0071]20 diameter of second bevel gear

[0072]21 mounting tab

[0073]22 supporting rim of gear cover

[0074]23 cross rib

[0075]24 blocking ribs

[0076]25 first longitudinal edge

[0077]26 second longitudinal edge

[0078]27 face edge

[0079]28 welded edge

[0080]29 width of welded edge

[0081]30 shaft feed-through of intermediate shaft

[0082]31 direction of rotation of second bevel gear

[0083]32 topside of grease pouch

[0084]33 height of cross rib

[0085]34 height of blocking rib

1. Arrangement of lubricating grease (2) inside the housing of a gearunit (1), wherein the gear unit has rotatable components, characterizedin that, prior to the initial startup of the gear unit (1), thelubricating grease (2) is enclosed by at least one grease pouch (3), theat least one grease pouch (3) is inserted into the housing of the gearunit (1) so as to lie close to at least one rotatable component, and theat least one grease pouch (3) tears open during the initial startupbecause of the action of the rotatable components and releases thelubricating grease (2).
 2. Arrangement as claimed in claim 1,characterized in that at least one edge (4) of the grease pouch (3) isarranged on a gear wheel of the gear unit (1).
 3. Arrangement oflubricating grease as claimed in claim 1 or 2 in the gear unit of a jack(5), wherein the gear unit (1) is at least partially arranged inside agear chamber (8) formed by a support tube (6) and a gear cover (7), hasa shaft (9) configured with a first bevel gear (10), wherein the firstbevel gear (10) meshes with a second bevel gear (11) that isnon-rotatably mounted on the gear-side end (13) of a spindle (12), andan inner tube (15) supported in the support tube (6) and engaging withthe spindle (12) via a spindle nut (14) can be telescoped in anextension direction (16) by a rotation of the shaft (9) in a firstdirection of rotation (17), characterized in that the grease pouch (3)is inserted into the gear chamber (8) with at least one edge (4) on thefirst bevel gear (10) and/or the second bevel gear (11).
 4. Arrangementas claimed in claim 3, characterized in that the grease pouch (3) isarranged in the gear chamber (8) on a pull-in side (18) of the bevelgears (10, 11) in the first direction of rotation (17).
 5. Arrangementas claimed in claim 3 or 4, characterized in that the grease pouch (3)has a width (19) that largely corresponds to the diameter (20) of thesecond bevel gear (11).
 6. Arrangement as claimed in any one of claims 3to 5, characterized in that the at least one edge (4) of the greasepouch (3) is attached to at least one bevel gear (10, 11) and/or theintermediate shaft (9) by means of an adhesive.
 7. Arrangement asclaimed in any one of claims 3 to 6, characterized in that the edge (4)of the grease pouch (3) has a mounting tab (21) that can be guidedbetween the intermediate shaft (9) and the second bevel gear (11). 8.Arrangement as claimed in any one of claims 3 to 7, in which the gearcover (7) on its underside has a protruding circumferential supportingrim (22) and a protruding cross rib (23), characterized in thatadditional blocking ribs (24) engage with the supporting rim (22) andthe cross rib (23).
 9. Arrangement as claimed in any one of claims 3 to8, characterized in that the grease pouch (3) has the features of claims10 to
 19. 10. Grease pouch (3) for receiving lubricating grease (2),particularly for insertion into a gear unit (1), characterized in thatthe grease pouch (3) is made of a composite material.
 11. Grease pouch(3) as claimed in claim 10, characterized in that the composite materialhas an inside polyethylene layer, an aluminum layer applied thereto, anintermediate polyethylene layer and an outer paper layer.
 12. Greasepouch (3) as claimed in claim 11, characterized in that the innerpolyethylene layer has a weight per unit area of 20 g/m² to 30 g/m². 13.Grease pouch (3) as claimed in claim 11 or 12, characterized in that thealuminum layer has a thickness of 5 μm to 10 μm.
 14. Grease pouch (3) asclaimed in any one of claims 11 to 13, characterized in that theintermediate polyethylene layer has a weight per unit area of 10 g/m² to15 g/m².
 15. Grease pouch (3) as claimed in any one of claims 11 to 14,characterized in that the outer paper layer has a weight per unit areaof 20 g/m² to 50 g/m².
 16. Grease pouch (3) as claimed in any one ofclaims 10 to 15, characterized in that the grease pouch (3) isrectangular with two opposite longitudinal edges (25, 26) and twoopposite face edges (27).
 17. Grease pouch as claimed in claim 16,characterized in that a first longitudinal edge (25) is configured as afolded edge and the opposite second longitudinal edge (26) and the faceedges (27) are configured as welded edges (28).
 18. Grease pouch asclaimed in claim 17, characterized in that the width (29) of thelongitudinal edge (28) of at least one face edge (27) increases in thedirection of the longitudinal edges (25, 26).
 19. Grease pouch asclaimed in any one of claims 10 to 18, characterized in that the greasepouch (3) is configured to receive an amount of lubricating greaseranging from 160 g to 200 g.
 20. Method for lubricating gear units (1)by means of lubricating grease (2), characterized in that, prior tostartup, at least one grease pouch (3) with lubricating grease (2) iscontacted with the gear unit (1), upon startup of the gear unit (1) atleast one component of the gear unit (1) tears open the at least onegrease pouch (3), such that the lubricating grease (2) is released andlubricates the gear unit (1), and the at least one grease pouch (3)remains in the gear unit (1) after startup.
 21. Method as claimed inclaim 20, characterized in that the grease pouch (3) dissolves byitself.
 22. Method as claimed in claim 20 or 21, characterized in thatthe grease pouch (3) is ground up by the gear unit (1).